Brush holder



Oct. 16, 1956 F. H. KEAT'ON ETAL BRUSH HOLDER 3 Sh eetsSheet 1 OriginalFiled Sept. 24, 1948 2.5: II Q: 3%?2 INVEyTORS.

0d. 16, 1956 F. KEATON ET AL 2,767,261

BRUSH HOLDER Original Filed Sept. 24, 1948 3 Sheets-Sheet 2 if iii Oct.16, 1956 F. H. KEATON EI'AL 2,767,261

BRUSH HOLDER Original Filed Sept. 24, 1948 lMu/MM United States PatentC) BRUSH HOLDER Frank H. Keaton and David C. Bettison, Omaha, Nebr.

Original application September 24, 1948, Serial No. 50,962. Divided andthis application April 4, 1951, Serial No. 220,120

5. Claims. (Cl. 191-49) Our invention relates to a carriage forintroducing high amperage, low voltage current into a rail for thepurpose of flaw detection, the carriage also being used to support theinductive pickup that searches the magnetic field above the rail fornon-uniformities in field strength, such nonuniformities generally beingindicative of discontinuities in the rail.

In electro-inductive rail flaw detection a pickup is used to measure thestrength of the magnetic field about the rail, the upper surface thereofnormally being the portion traversed by the pickup. Since the strengthof the surrounding field may vary about the difierent portions of therail and will vary at different distances from the same surface of therail, it is highly important that the pickup be maintained a constantdistance from the rail and that a substantially constant alignment ofthe pickup with respect to'the rail be kept during the detectionprocess. Y

;In view of the fact that it is necessary in the electroinductive systemof testing to search the rail with the pickup between the electricalbrushes that makecontact with the rail, it is generally the practice tomount both the brushes and the pickup on a unitary mount or carriage.One advantage of this is that it facilitates raising these elementsoifthe rail when they are not in use and again re-positioning them on therail when further testing is to be performed. However, the mounting ofboth the brushes andrthe pickup on a single carriage introduces somecomplications, for not only must the pickup maintain a constantorientation and spacing with respect to the rail, but the brushes,spaced out to either side of the pickup, must remain in contact with thetop surface of the rail and exert sufiicient pressure against thatsurface to insure the making of a good electrical connection.

Some of the factors which create difiiculties with conventional typecarriages or with supporting frames carried by the vehicle may bebriefly enumerated.

' 1. Constant orientation and alignment with respect to the rail must bemaintained not only when traversing straight track but also along curvesof varying radii. On curves such mountings will not conform to the arcof the rail curve but rather will be aligned with a chord of that are,thereby moving the pickup laterally away from the longitudinal axis ofthe rail.

2. Variations in the level of the rail between the supports for themounting will result in varying the spacing of the pickup to the rail.

A principal object of the present invention is to overcome the foregoingproblems and to provide a mounting in which the pickup and brushes willmaintain asubstantially constant orientation with respect to the railand1n which the pickup will be maintained a substantially constant distanceabove the upper surface of the rail.

"Additional objects and advantages include: amount,- ing which is easilyraised from, or lowered to, operative engagement with the rail; amounting requiring little or no maintenance over extended periods oftime; a spring biasing for the brush holder, which is readily accessiblefor adjustment of the pressure with which the brush bears against therail; a brush holder which will hold along brush thereby reducing thefrequency with which the brushes must be replaced, and in turn reducingthe loss from the discard of unusable brush stubs; and, a brush holderin which the brush clamps are located in a position easily reached toreplace the brushes or to increase the exposed length of the brush.

Additional objects and advantages will be apparent from the followingdescription read in conjunction with the drawings, in which:

Fig. 1 is a side elevation of a rail detector car;

Fig. 2 is a perspective view of the carriage frame upon which theelectrical contact brushes and pickup are mounted and showing the meansfor moving the carriage to and from the working position;

Fig. 3 is a section taken at line 3-3 of Fig. 1;

Fig. 4 is a perspective view of a pickup with the mounting bracketstherefor;

Fig. 5 is a plan view of the carriage;

Fig. 6 is a side elevation of the carriage;

Fig. 7 is a section taken at line 7--7 of Fig. 6;

Fig. 8 is a section taken at line 8-8 of Fig. 7; and

' Fig. 9 is a perspective view of a brush holder.

In the detection of flaws in rail a car 10, such as shown in Fig. l, isused to transport the detection apparatus, personnel and relatedequipment along the track with the detection process taking place enroute. In the electroinductive system of testing, the car will house thegenerator for providing the necessary current to energize the rail, therecording mechanism, under the supervision of one or more operators, toindicate the presence of nonuniformities in the magnetic field about therail, and the necessary equipment to provide the propulsive force formoving the car along the'track. The car is borne on flanged wheels 11,the axles of which are rotatably engaged in journal boxes 12 and 13. Thecar is supported through suitable springs from the journal boxes.

1 Carriage The brush carriage, indicated generally by 16, consists oftwo' frame members 17 and 18 positioned end to end substantially overthe rail With the adjacent ends of the members connected by means of auniversal joint 19. Frame member 17 is formed of a pair of spaced angleirons 20 and 21. At the end of member 17 adjacent member 18 (referred tofor convenience as the adjacen end) the angle irons are spaced by meansof end 23 of universal joint 19 and insulator blocks 24 mounted betweenend 23 of the universal joint and angle irons 20 and 21. Bolts or rivets26 serve to assemble the angle irons, insulator blocks, and end of theuniversal joint. Insulated sleeves 27 about the bolts or rivets 26, inconjunction with insulator blocks 24, prevent electrical contact frombeing mad -between the frame member 17 and the universal joint 19. 7

At the non-adjacent end of frame member 17 the angle irons are spaced byend 23 of support arm 29 and insulator blocks 31. Rivets 32 hold theangle irons securely assembled and attached to end 28 of support arm 29.

' Insulating sleeves 33 in conjunction with blocks 31prevent electricalcontact between frame member 17 and support arm 29.

Support arm 29 is bent as indicated at 33 in order that the outer end ofthe arm 34 will extend outwardly of the journalbox 12. Bolt 36, passingthrough longitu dinal slot 37 in arm 29, supports the arm from journalbox 12. The slot, coupled with the fact that the arm 29 is looselysupported between the head of bolt 36 and journal box 12, allows bothpivotal and longitudinal movements of the carriage with respect to thejournal box 12, which movements'are necessary to permit carriage 16 tobe raised and lowered as hereinafter described.

The construction of frame member 18 and its mounting by means of supportarm 38 is substantially identical th foregoing descriptionof framemember :17 and uppqrtarm 219 except that no provision is made forlongiiud nal movement of armt38 with respect to journal box 13. Ihenormal direction of ear movement during test' 11 QPerations is indicatedin Fig 1, and it will be seen i that J'Qul'nal 13 will be at the leadingend of the car. A! the leading end of the carriage it is desirable toonly allow pivotal movement ofi'thetcarriage with respect to tithe car,and thus no ,slot is provided inarm 38.

I 'Thearticnlated (adjacent) endsof framernembers '17 and 18 aresupported in constant alignment withthe' rail by means offlangediwheelAl conncted to fr ame 'mem ber lfi throughplates 42 and 43.Plates I42 and Hate ettachedito member 18tby means of -rivets iiwliicli' e61- IreSPQDd'QlLO rIiYCtS Z 6Yon frame member Bolt 46,interconnecting plates 42 and 43, forms an axlefor wheel 41.Insulatingibloeks' and sleeves prevent an electrical connection :betweenframe member 18, universal joint 19 and/or wheel 41.

a mechanism In manyins tancesa detector car must be movedrfrom poipt tqpoint without the necessity of performing fiaw detection en rgute. Insuch cases it is highly desirable 19 1. 19)? heelectrical contactbrushes out of engagement wi h the rail to prevent undue wear on thebrushes. To PSifiQXH) his f n 'tiqn we havetprovided a fluid-operatedpistgn mec hanism 51, and a spring 52 to lower and'raise, W eiy, thecarriage 16. (see Figs. 2 and 3). The pper epdgf thepiston mechanism 51and spring 52 are Q Q 9 ihetframe f thelcar 10 through insulating block53, thepu rpose of thfiblQCkl being to prevent elect i l eontaqt betweencar 10 and carriage 16. Bracket '55; afiigged to carriage frame member18,v is provided with an opening 556 into which is received the end ofpiston rodSfl Qf piston mechanism 51. Opening 56 is somewhat larger :indiameter than the end of piston rod 57 P Imit;=8 gular movement of thepiston rod with respect to'bracket 54. Semi-SPhetical-shaped member 58,

afiixed to piston rod 57,-'seats against'the upper face of 1 s sister;eise QW t r to, u e a dpubler n mechanism Ijbd i e nd lette -the. e A i.Q @15 h ve t e disa va es; f l Pre s r 0.11 the, nis anw nlcl s th ariase. 9, s 2me19n i afai re c fluid Pres re t *9. rai e. he carri sea dn Y t ni t esu rom inordinate "big ini r H l'ci iveriiig 6f theca rr iag a V hen-th car is t avel n i h u stin b in Pe me 'enw e t m y e d s blto suspen th car: iag q ahdk59; he n o W i ss1 ppdthr n h bailing 9 i brsk wer -ren eunq n qft e lro 'er i i r le aa m 1 er es t push, h a ria eou wardly to bring the flange of wheel 41 into engagement with the sideof the rail and to hold it there duringlhe testing procedure so' thatthe articulated P 116 1 of the carriage will maintaina definiteorientation with re'spect to the'r'ail. The: upper portion ofpiston'assernbly 61 is supported: from car '10'through insulatingbracket Q2, and the piston rod 63 of the assembly is aligned with andbears against bracket'54in the same manner as previous-1 y d sc d fo P ns mbl 5 nd Pis o mid 57 Spring 64, 'connected'at one end to'insulatingbracket 62- and at theother end to carriage bracket 54, ism;- tended bythe outward movement of piston rod 63. When the fluid pressure on pistonmechanism 61 is relieved, the spring will bring the carriage 16 inwardlyaway from 7 its position above the rail. Ball joint 66 at the upper endof piston assembly 51 allows that assembly to swing to facilitate theinward movement of the carriage '16. Similarly, a ball joint 67 at theupper end of piston assembly 61 allows that assembly to follow theppward downward rnovements of the carriage.

.T c pr s ure lewer ne the e rin s t9 st apply anathema o pt9n-asseml5ly 51 m bring'wheei 41 down against the top of the rail. Thecarriage -16Iwill at this point he swung somewhat inwardly by the actionof spring 64, although this displacement is not very large and thelength of wheel 41 is suflicient to assure that the wheel will come intocontact with the top of the a l, A ter the Wh e has come in restagainstltheltop 9; F 1? ai .flll tl M9 5 3? is app ed to piston assembly451 'msz in th a ria e ou wardlytand bringin'gthe flange 91 titan e q ena ementwith the side .otthe Irail. ilni mes y; L le t on hesetwopistonassembliesdur: maths: tsstin epe atiqn t gs kc pingnthe wheels-firmlyagainst the top of the rail with the flange of the wheel ares es asainhesisiep th rail 7 Thus, the adjacent end membe s 17 and 18 W l iemaintained at a .constan Q ken over the ail and'in -S 9Il$ 1n alignmentswith; r nnet t9 the rail 7 v sk-HP me nin T: The ran T 2 Pieter 7 a ahraqke fl a es? outer. l gffiflthe clip is pro! end f h? 2 i {3: 2 bf Sthre ddlin spe ng lower end' of flboltpqli" is over the. outer ,etol y-a.e t erlasrfaat ae'eaeei upper-end of the spring bears against theunder-face of clip 92, and the lower end of the spring bears against anut 98 threaded onto bolt 93. The nut may be moved up or down to adjustthe compression of the spring.

At the upper end of bolt 93 above .clip 92 is a nut 99 which, when thecarriage is lowered into engagement with the rail, will be spacedsomewhat from the upper face of clip 92 due to compression of spring 97by the pressure of brush 87 against the rail. The purpose of nut 99 isto allow only a limited extension of spring 97, and consequently thebrush holder, as the carriage is raised and the brush is no longerbearing against the rail.

Pigtails 101 are connected to the source of electrical energy within thecar and to the brush holders externally of the car. The pigtails may beattached to the upper end of bar 83 of the brush holder 81 through aconnecting screw, or by welding. Bar 83 is preferably made of a copperbase alloy and provides a low resistance path for the electrical currentto the brush, the resistance being sufliciently low that variations inthe length of the brush within tube 82 will not cause any appreciablechange in the voltage drop between the source of electrical current andthe end of the brush.

Operation From the foregoing description it will be appreciated that acarriage has been devised which is not only easily applied to a detectorcar designed for it, but also may be used in the conversion of existingdetector cars. It may be made to fit almost any size of existing carmerely by changing the lengths of support arms 29 and 38 and may bereadily hung from the existing journal boxes by the addition of bolts36. The only other necessary structural connection to the car is thatprovided through brackets 53 and 62, which may be easily mounted Withoutinvolving any fundamental changes in the existing car.

Initial adjustments include: pre-setting the position spring pressureused to hold the brush against the rail, which is done by means of nut98; setting nut 99 sufliciently above clip 92 to allow for some wear ofthe brush before the brush must be re-set and yet sufliciently close toclip 92 that the brush will be well above the upper surface of the railwhen the carriage is moved into raised position; and positioning pickup71 in the desired alignment and distance to the rail.

Before starting each days testing run, or oftener if necessary, theoperator of the car should examine each brush mounting to observe thespacing between nut 99 and clip 92. If the space is not adequate toallow for the wear of the brush until the next inspection period, setscrew 86 may be loosened and the brush may be extended a greaterdistance from the holder, whereupon the set screw is again tightened.Due to the positioning of the set screw at the bottom end of the brushholder, it is a very simple matter to make this correction with thecarriage suspended in the raised position. The particular mounting ofthe brush holder from the carriage permits tube 82, in which the brushis held, to be made much longer than has been possible with priordevices. A longer brush holder allows the use of correspondingly longerbrushes with an increase in the wear of an individual brush and with adecrease in the loss occasioned by the discard of unusable brush stubs.

After the length of the brushes has been correctly adjusted, fluidpressure is applied to piston mechanism 51 to lower the carriage and topiston mechanism 61 to move the carriage outwardly, with the flange ofguide wheel 41 in contact with the inner face on the rail. Wheel 41,being held securely in contact with the upper and side faces of therail, will assure that the adjacent ends of frame members 17 and 18 aremaintained at substantiaily constant distances above the upper face ofthe rail and in substantially constant alignments with respect to thelongitudinal axis of the rail.

The pickup, being supported from the adjacent end of frame member 17,will be held in the pie-set ali nment and spacing from the rail. The useof the detector car on straight track or curved track of varying radiiwill cause no substantial change in the positioning of the pickup, norwill low spots in the track vary to an appreciable extent the spacing ofthe pickup to the rail.

The brushes, being spaced only a short distance to either side of theuniversal joint, will reflect only to a very limited extent themovements that may occur in the outer ends of support arms 29 and 38.The brushes will at all times maintain a substantial face contactwith'the upper surface of the rail and insure a good electricalconnection thereto. v

It should be understood that the particular embodiments of the inventionshown in the drawings anddescribed herein are for the purpose ofcomplying with Section 112, Title 35, of the United States Code andshould not be construed as imposing limitations on the appended claimsexcept as may be required by the prior art.

The present application is a division of application Serial No. 50,962,filed September 24, 1948, now Patent No. 2,582,440.

We claim:

1. A brush mounting for use with rail flaw detector cars of the typewhich require as a part of their operation the passage of a strongelectrical current between spaced points in a rail beneath the car, saidmounting including a longitudinally extending support member positionedabove the rail and adapted to be raised and lowered with respect to therail, a plurality of coplanar brush assemblies pivotally mountedadjacent their upper ends in closely spaced longitudinal relationship onsaid support member, each such brush assembly including a tubular brushholder of substantially uniform cross-sectional shape throughout itslength and adapted to receive a brush which initially is ofsubstantially equivalent length, said support member including laterallyextending portions forming a plurality of first connection pointsarranged in closely spaced longitudinal relationship and each locatedrearwardly of the pivotal mounting for its associated brush assembly andproviding lateral clearance with respect to said associated brushassembly, each of said brush assemblies carrying a laterally extendingelement defining a plurality of second connection points arranged inclosely spaced longitudinal relationship and being substantiallycoplanar with said first connection points, each of said secondconnection points being located below the pivotal mounting for itsassociated brush assembly and adjacent its lower end and providinglateral clearance with respect to its associated brush assembly, and aplurality of resilient means each including a compression spring and astop means acting between said first and second connection points foryieldingly supporting said brush assemblies in trailing position whenthe support is raised, and resiliently urging the assemblies toward therail when the support is lowered, said first and second connectionpoints being positioned so that each such resilient means extends in adirection substantially normal to its associated brush assembly.

2. A brush mounting as set forth in claim 1 in which said resilientmeans are adjustable with respect to the downward forces exerted by saidcompression spring.

3. A brush mounting as set forth in claim 1 in which each of the brushassemblies includes a tubular brush holder pivotally mounted on thesupport member, a replaceable rod brush of uniform cross sectiondisposed within said holder, and releasable locking means carried bysaid holder beneath said second connection point and adjacent the bottomof said holder, said releasable means having its innermost surface inengagement with side surface portions of said brush to accommodatelengthwise adjustments of said brush within said holder.

4. A brush mounting as set forth in claim 1 wherein ggbiipgpgi11t5gndeggh of said jesilieni means includes 1. 1N 2 3 91 1 2; itslower endftoione of said ,seco'nd @mwipg paints .apd having {its upper andpassing fl ggggh said apertuyed ,hragket with the compression springtelesppped over said bolt and hearing at its upper end pp gaigl bracketand at its lower .end 011 an adjustable put threagiegilypeqeived on thelower end of said bolt.

1 ,5- A hlll h mountin as .set forth in claim 4111 which lsaidu tgpm ansi des an jus ble 510p 0111116 upper sxi of S id bplt ab s id bracket-References Cited in the flle of this'patent 1 NITED SIATES PATENTS 7Maxim June 8,1880 7 'Kenningfon et a1. Nov. 10,1903 Stiawbridge May-6,1924 Schaa'keet a1. Aug. 16, 1932 JBillste'in et a1. Oct. 27, 1-937 7:Kaeh ns V- Feb 15, 1949 V FOREIGN PATENTS i Great Britain Oct. 14, 19077 Great Britain Nov. 12, 1903 V

